Part of #18714: Replacing deprecated constants in Avatar-Favicon folder

[rohiiittttt]

Explanation

• This PR is a part of Replace deprecated constants with enums #18714

Replaced deprecated design system and storybook constants in the Avatar-Favicon folder
ui/components/component-library/Avatar-Favicon

Screenshots/Screencaps

Before

After

jest test

Manual Testing Steps

Pre-merge author checklist

• I've clearly explained:
  • What problem this PR is solving
  • How this problem was solved
  • How reviewers can test my changes
• Sufficient automated test coverage has been added

Pre-merge reviewer checklist

• Manual testing (e.g. pull and build branch, run in browser, test code being changed)
• PR is linked to the appropriate GitHub issue
• IF this PR fixes a bug in the release milestone, add this PR to the release milestone

If further QA is required (e.g. new feature, complex testing steps, large refactor), add the Extension QA Board label.

In this case, a QA Engineer approval will be be required.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[rohiiittttt]

I have read the CLA Document and I hereby sign the CLA

[rohiiittttt]

hey @georgewrmarshall can you please review this PR?
thanks.

[georgewrmarshall]

LGTM! Thanks for your contribution

[codecov]

Codecov Report

Merging #19332 (e344874) into develop (c146023) will decrease coverage by 0.01%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           develop   #19332      +/-   ##
===========================================
- Coverage    70.05%   70.05%   -0.01%     
===========================================
  Files          963      963              
  Lines        37248    37248              
  Branches      9630     9630              
===========================================
- Hits         26094    26092       -2     
- Misses       11154    11156       +2     

Impacted Files	Coverage Δ
...component-library/avatar-favicon/avatar-favicon.js	90.91% <ø> (ø)

... and 2 files with indirect coverage changes